Hydrostatic drive

ABSTRACT

A vehicle suspension and hydrostatic drive system in which the driving engine, the fluid pump, the fluid motors and the driven wheels are suspended from the vehicle frame as a unitary package. The engine pump unit is connected to each motor unit by a truss having the upper and lower horizontal truss members formed by rigid fluid conduits and the end truss members formed by the pump and motor housings and intermediate diagonal truss members. The trusses are bowed so the center of weight of the engine pump unit and each motor unit are on a transverse axis. The fluid motors have a central spindle providing rotary support for the driven wheels. Single needle bearings located between each motor housing and the driven wheel provide thrust or axial support for the wheels.

United States Patent Hause 51 Sept. 12, 1972 [54] HYDROSTATIC DRIVE420,616 4/ 1947 Italy ..180/66 A [72] Inventor: Gilbert K. Hause,Bloomfield Hills,

Mich Primary Examiner-Ben amin Hersh Assistant Examiner-Milton L. Smith1 Asslsnw General Motors Common, Attorney-W. E. Finken, A. M. Heiter andD. F.

Detroit, Mich. Scherer [22] Filed: Oct. 5, 1970 [57] ABSTRACT [21] Appl.No.: 77,941

A vehicle suspension and hydrostatic drive system in which the drivingengine, the fluid pump, the fluid mos s s a a Q a s l a I a a a s a a nn s I s a I a u u u u I s a s s n a a a a a n u a s s a s a I Q a as a[58] of Search "180/66 2 unit is connected to each motor unit by a trusshaving I the upper and lower horizontal truss members formed 56 R t Ct dby rigid fluid conduits and the end truss members 1 e I e formed by thepump and motor housings and inter- UNITED STATES PATENTS mediatediagonal truss members. The trusses are bowed so the center of weight ofthe engine pump unit 1,773,587 8/1930 Lape 18043651; and each motor unitare on a transverse axis The fluid 1,111,525 9/ 1914 Coppock motors havea central spindle providing rotary Support 3,439,766 4/1969 Dence et a1...180/66 F for the driven wheels Sin le needle head 8 located 9/1966Thurber ..1 80/66 F ux 3273464 between each motor housing and the drivenwheel FOREIGN PATENTS 0R APPLICATIONS provide thrust or axial supportfor the wheels.

945,431 7/ 1956 Germany ..180/66 F 2 Claims, 6 Drawing FiguresPATENTEDSEP 12 m2 3.690.398

sum 1 or 2 ATTORNEY HYDROSTATIC DRIVE This invention relates to vehicledrive systems and more particularly to hydrostatic drive systems inwhich the drive components are suspended from the vehicle frame as aunitary package.

In the present invention, the driving engine and the fluid pump for thehydrostatic drive system are drivingly connected and secured together toform a single power unit. The fluid pump is fluidically connected todrive motors in each of the vehicle driving wheels by rigid conduitswhich conduct fluid from the pump to the motors to provide a drive forthe vehicle. The conduits are suspended from the vehicle frame by a pairof springs. Thus, the entire drive package, engine, pump, motors anddriving wheels are suspended as a unitary package from the vehicleframe.

Each fluid motor has a central spindle which rotatably supports thedriving wheel. A needle bearing disposed between the housing of thefluid motor and the driving wheel provides axial or thrust support forthe wheel on the spindle. This provides a simple support system for thedriving wheel and eliminates the need of taper roller bearings presentlyused on most driving wheels.

The conduits form a rigid connection between the pump and motors andcontrol the spacial relationship between the pump and the drivingwheels. Leaf springs secured to the conduits and the vehicle framemaintain the position of the driving system relative to the vehicle.Therefore, the driving system including the pump and hydrostatic motorscan move relative to the vehicle frame to absorb road shock andvibrations.

It is, therefore, an object of this invention to provide an improvedvehicle suspension and drive system, an engine fluid pump, fluid motorsand driving wheels connected in a unitary package and suspended from thevehicle frame.

Another object of this invention is to provide in an improved unitarydrive package a fluid motor having a central spindle providing rotarysupport for a driving wheel and a single thrust bearing providing axialsuport. I p These and other objects and advantages of the presentinvention will be more apparent from the following description anddrawings in which:

FIG. 1 is a plan view of the vehicle frame, drive and suspension;

FIG. 2 is an end view of the vehicle drive and suspension system; FIG. 3is a plan view of one-half of the drive system;

FIG. 4 is a cross-sectional view of the fluid motor and drive wheels;

FIG. 5 is a view taken along line 5-5 of 6-and FIG. 6 is an elevationalview partly in section taken along line 6 6 of FIG. 5.

Referring to the drawings particularly FIGS. 1, 2 and 3 wherein likecharacters designate like or corresponding parts, there is shown aninternal combustion engine 10 secured to and drivingly connected with ahydraulic pump 12. The engine 10 is a conventional internal combustionengine of the horizontally opposed piston type having a housing 13 andan output shaft, not shown. The pump 12 is a conventional variabledisplacement radial piston pump having a servo control 14 forcontrolling the displacement of the fluid pump and, therefore, the fluiddelivered to the drive motors, a

housing 15 and an input shaft, not shown, drivingly connected with theoutput shaft of the engine. The pump housing 15 is secured to the enginehousing 13 and has a pair of vertically spaced fluid ports 17 and 19connected to a pair of rigid conduits l6 and 18 respectively which areconnected to mounting brackets 20 which are shackled to leaf springs 22by U-bolts 24 and 26. The leaf springs 22 are also connected to thevehicle frame 27. Also connected to the bracket 20 is a rigid conduit 28having a pair of fluid channels therein 30 and 32 separated by a centralwall 34. The conduit 28 is in fluid communication with a fluid motorgenerally designated 36. The conduits l6 and 18 are secured together bya plurality of struts 35 to provide reinforcement to the structure. Thepump housing 15 and the bracket 20 cooperate with the conduits l6 and 18and the struts 35 to form a truss 37 having sufficient structuralstrength to support the engine 10, pump 12 and motors 36.

The fluid motor is a conventional radial piston motor having a centralspindle 38 in fluid communication with the conduit 28, a sleeve member40 rotatably mounted on the spindle 38, a plurality of pistons 42secured to the sleeve 40 and slidably engaged in cylinders 44 which areslidably abutting the motor housing 46. The fluid channels 30 and 32provide vertically spaced inlet and outlet ports for the motor 36 facingthe pump ports 17 and 19. The motor housing 46 is secured to a drum 48which is secured or formed integrally with the bracket 20. Thus, thehousing 46 and the drum 48 are stationary. A lip seal 50 is disposedbetween the housing 46 and the sleeve 40 to prevent fluid from leakingto atmosphere past the end of sleeve 40. A thrust bearing such as needlebearing 52 is disposed between the drum 48 and the sleeve 40. The needlebearing 52 is positioned by a plurality of snap rings 54, 56 and 58, soas to permit relative rotation between the drum 48 and the sleeve 40 andalso absorb the axial thrust loads that may be placed on the sleeve 40.The axis of the spindles 38 are aligned and lies in a plane containingthe center of weight of the engine 10, pump 12, truss 37 and motor 36,thereby reducing the torsional stresses on the truss 37.

The sleeve 40 has a threaded end portion 60 and a hexagonal portion 62.The hexagonal portion 62 is adapted to mate with a drum 64 which issecured to the spindle 12 by a fastener 61. The drum 64 has a pluralityof fasteners 66 secured thereto to permit mounting of a driving wheel 68thereon. A plurality of fasteners 70 secure the driving wheel to thedrum 64. Thus, when the sleeve 40 is rotated by fluid delivery to themotor 36, the driving wheel 68 will be rotated with the sleeve 40.

When the engine is rotating and therefore driving the fluid pump 12,fluid pressure is delivered through either conduit 16 or 18 to the fluidmotor 36 depending upon the position of the servo valve 14. If fluidpressure is delivered through conduit 16, the fluid will pass throughpassage 30 to the fluid motor 36 where it will be delivered throughopenings 72 in the spindle 38 to the pistons 42 and cylinders 44. Thefluid pressure in the pistons 42 and cylinders 44 will cause relativelinear movement between the pistons and cylinders, thereby causing thesleeve 40 to rotate. As the sleeve 40, pistons 42 and cylinders 44rotate, the fluid will be delivered from the cylinders 44 through thepassage 32 and the conduit 18 to the pump 12. If it is desired to rotatethe motor in the opposite direction, the servo 14 is adjusted by theoperator so that fluid pressure is delivered through passage 18 to themotor 36 and returns to the pump 12 through passage 16.

Obviously, many modifications and variations of the present inventionare possible in light of the above features. It is, therefore, to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than is specifically described.

What is claimed is:

1. In a vehicle suspension and drive system, an engine; a fluid pumpdrivingly connected to said engine; a pair of driving wheels; fluidmotor means drivingly connected to the driving wheels each motor meanshaving spindle means for rotatably supporting said driving wheels andsingle thrust bearing means for axially supporting said driving wheelson said spindle means; fluid conduit means for providing fluidcommunication between said pump and motors and forming a portion of thesuspension system for the vehicle including vertically spaced fluidconduits secured to said pump and each of said motors, and strutssecured between said fluid conduits to form therewith a structural trusscomponent in the suspension system, said fluid conduits being laterallybowed to locate the center of weight of said engine and pump on the axisof said spindle means; and spring means secured between the vehicleframe and said conduit means for suspending the engine, pump, motors,and drive wheels from the frame in a unitary package.

2. In a vehicle suspension and drive system, a vehicle frame, an enginehaving a housing and an output shaft;

a fluid pum having an input shaft drivingly connected to said engineoutput shaft and having a housing rigidly secured to said engine housingand said pump housing having an oppositely facing horizontally extendingpair of inlet ports and an oppositely facing horizontally extending pairof outlet ports with one pair of said ports at the extreme top and theother at the extreme bottom of said housing to provide a substantialvertical arc between said pairs of ports; a pair of fluid motor meanshaving a housing having a bracket secured thereto having verticallyspaced inlet and outlet ports each facing the pump outlet and inletports respectively on the adjacent side of the pump; a pair ofvertically spaced horizontally extending rigid fluid conduits betweensaid pump and each bracket connected between said pump outlet port andsaid bracket inlet port and between said pump inlet port and saidbracket outlet port for providing fluid communication between said pumpand motors and structurally secured to said pump housing and bracketproviding upper and lower truss members and forming with said pumphousing and bracket acting as end verticals of a truss portion of thesuspension system for the vehicle between said pump and each motor; andspring means secured between the vehicle frame and a conduit adjacenteach bracket for suspending the engine, pump and motors in a unitarypackage; a pair of driving wheels, each fluid motor drivingly connectedto a driving wheel, each motor having a spindle for rotatably supportinga driving wheel and single thrust bearing means for axially supportingsaid driving wheel on sai s indle means; said air f fluid cond its beibowe la ierally to locate th weight center of said e ii gine pump uniton the axis of said spindles.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO- g ggnqqst Dated September 12, 1972 lnvencorlls) Gilbert K. Hause It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line 54, "of 6-and" should read --of Figure 3-and-- Signed andsealed this 13th day of February 1973 (SEAL) Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

1. In a vehicle suspension and drive system, an engine; a fluid pumpdrivingly connected to said engine; a pair of driving wheels; fluidmotor means drivingly connected to the driving wheels each motor meanshaving spindle means for rotatably supporting said driving wheels andsingle thrust bearing means for axially supporting said driving wheelson said spindle means; fluid conduit means for providing fluidcommunication between said pump and motors and forming a portion of thesuspension system for the vehicle including vertically spaced fluidconduits secured to said pump and each of said motors, and strutssecured between said fluid conduits to form therewith a structural trusscomponent in the suspension system, said fluid conduits being laterallybowed to locate the center of weight of said engine and pump on the axisof said spindle means; and spring means secured between the vehicleframe and said conduit means for suspending the engine, pump, motors,and drive wheels from the frame in a unitary package.
 2. In a vehiclesuspension and drive system, a vehicle frame, an engine having a housingand an output shaft; a fluid pump having an input shaft drivinglyconnected to said engine output shaft and having a housing rigidlysecured to said engine housing and said pump housing having anoppositely facing horizontally extending pair of inlet ports and anoppositely facing horizontally extending pair of outlet ports with onepair of said ports at the extreme top and the other at the extremebottom of said housing to provide a substantial vertical arc betweensaid pairs of ports; a pair of fluid motor means having a housing havinga bracket secured thereto having vertically spaced inlet and outletports each facing the pump outlet and inlet ports respectively on theadjacent side of the pump; a pair of vertically spaced horizontallyextending rigid fluid conduits between said pump and each bracketconnected between said pump outlet port and said bracket inlet port andbetween said pump inlet port and said bracket outlet port for providingfluid communication between said pump and motors and structurallysecured to said pump housing and bracket providing upper and lower trussmembers and forming with said pump housing and bracket acting as endverticals of a truss portion of the suspension system for the vehiclebetween said pump and each motor; and spring means secured between thevehicle frame and a conduit adjacent each bracket for suspending theengine, pump and motors in a unitary package; a pair of driving wheels,each fluid motor drivingly connected to a driving wheel, each motorhaving a spindle for rotatably supporting a driving wheel and singlethrust bearing means for axially supporting said driving wheel on saidspindle means; said pair of fluid conduits being bowed laterally tolocate the weight center of said engine pump unit on the axis of saidspindles.